EXPLORATION ’93 — Louvicourt on-line for 1994 production

Development of the Louvicourt base metal deposit, near Val d’Or, Que., is proceeding as planned, with production expected to begin in July, 1994.

“We are very pleased with the progress of the project and the way the joint venture is working” says Howard Stockford, executive vice-president of Aur Resources (TSE). The $350-million project is being developed by Aur and partners Teck (TSE) and Novicourt (TSE), the latter being controlled by Noranda (TSE).

Underground work is on schedule, the production shaft is 95% complete (having reached 900 metres) and lateral development from the exploration shaft is in progress on three levels.

Systematic drilling of the deposit on 30-metre centres, starting at the eastern edge of the deposit and progressing westward, is continuing from an exploration drift in the hangingwall on the 655-metre level. The 75,000-metre program, designed to upgrade reserves into the proven and probable categories, is now 50% complete.

The deposit is in the southwest part of the Louvicourt property, about 800 metres north of Hwy. 117 and one mile east of the shaft of the old Louvem mine.

It lies within a 1.6-km-wide unit of felsic volcanic rocks which can be traced for more than 40 km from the western part of Bourlamaque Twp., through Louvicourt Twp. and east into Vauquelin Twp. Regionally, this unit hosts important massive sulphide occurrences, including the past-producing East Sullivan, Manitou, Dunraine and Louvem mines.

During the 1950s and 1960s, the property was explored for gold by several operators. Soquem optioned the property in 1967 and subsequently discovered the Louvem copper deposit. Over its 10-year life, the mine produced more than 1.9 million tons of copper-zinc ore.

In 1987, Aur optioned the property and began systematically exploring the Louvem ore horizon. Late 1988 saw the intersection of banded sulphides and a 118-metre interval of stringer copper mineralization grading 0.83% copper. The discovery of the deposit followed several months later.

The ore is hosted by an 240-metre-thick volcano-sedimentary unit of interbedded fine ash and lapilli tuffs and laminated cherts which dip 70-80 to the north.

The ore horizon is underlain by a sequence of rhyolitic flows and breccias and overlain by intermediate volcanic flows and shallow-level intrusive rocks. Economic copper-zinc mineralization occurs in a series of closely spaced, stacked, semi-massive-to-massive-sulphide lenses which grade laterally into zones of stringer chalcopyrite and/or disseminated pyrite mineralization. Six distinct lenses have been defined, of which the A-3, A-4 and A-5 contain the bulk of the reserves. Individual ore lenses range in thickness from 3 to 60 metres. The deposit has a strike length of 550 metres between vertical depths of 400 to 915 metres.

Mineralization consists primarily of massive chalcopyrite-sphalerite-pyrite zones which frequently contain bands of exceptionally rich massive chalcopyrite mineralization.

Prior to the underground drill program, estimated minable reserves were 24 million tonnes grading 3.89% copper, 1.95% zinc and 1.2 grams per tonne gold and 31 grams silver, based on a 4,000-tonne-per-day mining rate and a copper equivalent cutoff which declined from 4% to 2% over a 17-year mine life. These reserves extended from a depth below surface of 300-850 metres. Preliminary underground drill results indicate that the eastern edge of the deposit, below a depth of 625 metres, is about 80 metres west of what was suggested by surface drilling. The drilling has also outlined previously unrecognized zinc-rich mineralization extending to a depth of at least 900 metres on the eastern edge of the deposit. The plunge of the deposit also appears to be steeper then previously indicated, which would allow for new copper and zinc reserves to exist below 770 metres.

On surface, construction of the mill facilities are about a month ahead of schedule. The mill will employ conventional flotation to produce separate zinc- and precious-metal-bearing copper concentrates. The copper concentrates will be smelted by Noranda.

Construction of the tailings storage facility has been completed. To prevent acid generation from mine waste, Louvicourt will employ a sub- aqueous tailings disposal system. With this technique, tailings are covered with one metre of water to prevent interaction with the air. To date, expenditures on the Louvicourt deposit, owned 30% by Aur, 25% by Teck and 45% by Novicourt, total slightly more than $100 million.